Not able to create Mailbox using Solid CP

Currently i am facing error while creating New Mailbox via SolidCP. I have integrated it with exchange 2016. I am also able to create org , Contact using Solid CP but when i am trying to create mailbox it gives me below error.

Error

Connecting to remote server webmail.hostingcloudapp.net failed with the following error message :
The WinRM client sent a request to an HTTP server and got a response saying the requested HTTP URL was not available.
This is usually returned by a HTTP server that does not support the WS-Management protocol.